Big Bill Neidjie (c. 1920 – 23 May 2002) was the last surviving speaker of the Gaagudju language, an indigenous language from northern Kakadu after which the World Heritage-listed Kakadu National Park is named. He was a senior elder of Kakadu National Park and a traditional owner of the Bunitj estate in northern Kakadu, perhaps the most spectacular National Park in Australia. His decision to open up this land to other people was instrumental in the creation of Kakadu National Park. He was usually called Big Bill Neidjie because of his physique and physical strength, probably gained through his time working on the luggers, and was also called Kakadu Man, after the title of his first book.
He was born at Alawanydajawany on the East Alligator River around 1920 into the Bunitj clan of the Gagudju people. His father was Nadampala and his mother was Lucy Wirlmaka, from the Ulbuk clan of the Amurrak people. He grew up leading a traditional lifestyle in the East Alligator region, and was taught by his father, his grandfather, and others how to hunt and manage his environment. From about the age of 20 he worked first with buffalo hunters, then at a timber mill, and then on board a lugger transporting people and goods along the North Coast of the Northern Territory and to remote island communities. He was initiated at a ceremony at Ubirr in the early 1940s. During the Second World War he helped in the defence of Australia, working at the radar station at Cape Don. He was in Darwin during the Japanese bombings in 1942 and helped Aboriginal people during and after the devastation.
Big Bill was instrumental in the decision to lease his traditional lands to the Commonwealth of Australia so that it could be managed as a wild area and as a resource to be shared by all Australians. After helping establish Kakadu as a National Park in 1979, he returned there to commit the rest of his life to supporting the joint management of the Park. Kakadu continues to be governed by a board with a majority of indigenous Australians. In 1988, Kakadu was featured in the February issue of The National Geographic Magazine, and was the focus of the National Geographic television documentary entitled Twilight Of The Dreamtime, in which Big Bill figured prominently. His son, Jonathan Yarramarrna appeared with him and parts of the film dealt with the future of Kakadu and specifically with Big Bill's preparation for Jonathan to assume the custodianship of his family's tribal lands. In 1989 he was awarded the Order of Australia for his services to conservation.
In many indigenous Australian cultures, there are traditional secrets passed down from generation to generation, and it is taboo to reveal these secrets to a non-initiate. As he grew older, Bill Neidjie realised that he might be in the position, as one of the last Gagudju initiates, of taking these secrets to the grave with him, and so made the courageous decision to break this taboo, so that his culture might live on. In addition to entrusting some of the custodianship of tribal lands to his son Jonathan, he related many of his stories to the anthropologist Stephen Davis and others, and published two books, in which he related his passion for the land of which he was part, and insisted on the importance of managing the land in the traditional ways. He hoped that, one day, his culture might thrive once again, and his grandchildren, or their grandchildren, might pick up the threads once more.
Bill Neidjie died on 23 May 2002. The Federal Minister for the Environment and Heritage, David Kemp, said, "He was instrumental in the establishment of Kakadu National Park and was deeply committed to sharing his love for his country, his respect for the heritage of his country and his indigenous culture with countless thousands of park visitors and all who shared his love for the natural world."